Furnace for heating metal



(No Model.)

J.- W. PARMELEE.

FURNACE FDR HEATING METAL.

No. 430,538. PatentedJune 17, 1890 avwo'ntoz Ja7zzz-7ffparmlee Wat-team?UNTTED STATES PATENT OFFICE.

J OIIN IV. PARMELEE, OF I VILKES-BARRE, PENNSYLVANIA.

FURNACE FOR HEATING METAL.

SPECIFICATION forming part of Letters Patent No. 430,538, dated June 17,1890.

Application filed March 20, 1888. Serial No. 267,893. (No model.)

To all whom it may concern.-

Be it known that 1, JOHN W. PARMELEE, a citizen of theUnitedStates,resid in g at W'ilkes- Barre, in the county of Luzerne and Stateof Pennsylvania, have invented a new and useful Improvement inAnnealing-Furnaccs, of which the following is a specification.

Myinvention relates to an improvementin furnaces for annealing orhardening purposes, especially designed to heat axles or axle-boxes to aohcrry-red; and it consists in the peculiar construction and arrangementof parts that will be more'fully set forth hereinafter, and particularlypointed out in the claims.

The object of my invention is to provide a furnace having a hearth-whichis adapted to permit the caloric currents to circulate both over andunder the hearth,so as to subject the same to a maximum degree of heatwith a minimum expenditure of fuel, and this Ohjcct I attain by theconstruction illustrated in the accompanying drawings, in which Figure 1is a vertical central longitudinal sectional view of anannealing-furnace embodying my improvement. Fig. 2 is a verticaltransverse sectional view of the same, taken 011 the line a; 00 ofFig. 1. Fig. 3 is a similar view taken on the line "y y of Fig. 1. Fig.4is a horizontal section taken on the line .2 z of Fig 1, parts of thehearth being omitted in order to display the arrangement of the heatingfines or passages under the hearth.

A represents the annealing-furnace, which is provided at one end with acombustionchamber B, which is separated by the grate C from the ash-pitD. In the front wall of the furnace, at a suitable height above thegrate, are a number of fuel-openings E, on the under sides of which arearranged downwardly-inclined chutes F. The rear side of thecombustion-chamber and of the ash-pit is formed by a bed of masonryG,which rises to a suitable height above the grate and extends ncarlytothe rear wall of the furnace, thereby forming an open space or flue Hbetween the said bed and the rear wall of the furnace.

I represents the smoke pipe or stack, which is erected on the rear endof the furnace and communicates at its lower end with a flue or spaceII.

On the upper side of the bed G, and extending throughout the entirelength thereof are a series of Walls or partitions K, the centralportions of which are only half asthick as the end portions thereof. Thesaid walls or partitions are arranged comparativelyclosely together onthe center of the bed, and are arranged at regularly-increasingdistances apart from the center to the sides of the bed. so that'the'channels L or flues which are formed between the said walls orpartitions willbe wider at the sides of the furnace than the channelswhich are nearer the center thereof. By male ing the walls or partitionsnarrower at their central portions than at their ends abutting oifsets Mare formed at the ends of the said partitions or walls, for the purposeto be hereinafter set forth.

The space in the flue L between the offsets M is twice the thickness orwidth of the end portions of the lines.

N represents the hearth. which is arranged directly over the tlues orchannels L, and is supported on the walls or partitions K at a suitableheight from the bottoms of the channels or lines. This hearth extendsfrom the front side of the bed to the rear side thereof, thus leavingthe upper end of the space or flue II between the rear ends of the wallsor partitions K unobstructed and in communication with theheating-chamber 0 above the hearth.

The rear wall of the furnace is provided with a suitable number ofopenings P, which are covered by sheets of mica, and through which thematerial on the hearth may be inspected when the furnace in operation.In one side of the furnace, near the bottom thereof, is an openingR,Which communicates with the flue or space II, the function of the saidopening being to supplyair to the furnace in suitable quantities tofacilitate the draft up the chimney or stack, and thereby promote activecombustion of the fuel on the grate.

The hearth is provided on its front side with the usual bridge-wall S.

The operation of my invention is as follows: Vhen the furnace is inoperation, the caloric currents from the fire box or chamber pass overthe hearth and downward through the fine or space 11, through the stackor chimney, and caloric currents also pass through ted.

the channels L under the hearth, and thus the hearth is heated both fromits upper and its lower sides. It Will thus be seen that the products ofcombustion from both above and below the hearth must pass down beforereaching the stack.

The offsets M at the ends of the partitionwalls K cause the caloriccurrents to eddy in the said channels L, and thereby impart the maximumamount of heat to the bottom of the hearth, inasmuch as the heat isthereby caused to be retained in the channels longer than would be thecase were the offsets omit- The said channels L are made wider at thesides of the hearth than at the center thereof, for the reason that thesides of a furnace are usually at a somewhat lower temperature than thecentral portion thereof, and

by widening said channels as they near the sides of the furnace thecapacity of the channels is increased, and the caloric currents whichpass through the said outer channels are of greater volume than thosewhich pass through the central channels, and consequently all parts ofthe hearth are maintained at a uniform temperature.

A damper Q is provided in the smoke-stack to regulate the draft andcause the caloric currents to remain in the heating-chamber time enoughto effect the desired results.

The extension of the flue II below the heating-chamber 0 enables theflue to be cleaned through the opening R.

Having thus described nly invention, I claim- 1. An annealing-furnacehaving the firebox, the hearth arranged above the plane of the lire-boxand to one side of the same, and the channels arranged under the hearthand communicating with the fire-box,and also with the escape-fines, saidchannels having their partition Walls made thicker at different points,so as to form the offsets or shoulders H, and being thereby adapted tocause the caloric currents to eddy under the hearth, substantially asdescribed. i

2. An annealing heating-furnace having the fire-box and the hearth aboxe the fire-box and to one side of the same, the channels L, formed underthe hearth and communicating with the fire-box to receive the gasestherefrom, and the escape-fines with which the channels L alsocommunicate, said channels having the offsets or shoulders M, and beingthereby adapted to cause the caloric currents to eddy under the hearth,said channels being made wider at the sides of the hearth than at thecenter of the same, for the purpose set forth.

In testimony that I claim, the foregoing as my own I have hereto affixedmy signature in presence of two witnesses.

JOHN W. PARMELEE. WVitnesses:

E. G. SIGGERS, FRANK W. PARMELEE.

